A guide to green infrastructure

Explainer

Walking path under jacaranda trees in the Brisbane green infrastructure

The word “infrastructure” generally summons up images of roads, railways, power stations and shiny new bridges. But it’s a concept that includes all the features and systems that support urban environments, including water management, maintaining a comfortable habitat and providing pleasant places to live or work in.

Green infrastructure refers to the use of natural features and elements to provide these essential functions. For example, an avenue of trees that cleans the air, shades footpaths and absorbs storm water runoff.

Urban planners, landscape designers, local councils and property developers are all jumping aboard the trend to make urban landscapes more sustainable.

Water

Water management features heavily in green infrastructure. Landscaped swales and rain gardens can manage local storm water runoff, while many councils and estate developers are installing wetlands to store runoff.

Wetlands highlight an important aspect of green infrastructure:  unlike a concrete culvert, a nature-based or biomimicry solution like a swale or wetland manages water but also helps improve air quality, provides habitat for biodiversity, cools the surrounding area on hot days, and stores carbon.

Nature

They also tap into our inherent love of nature. Looking at green spaces and living plants is good for our mental and physical health, a benefit we can’t derive from staring at a concrete culvert.

Research into which kinds of plants work best for purifying water shows that reed beds and other semi-aquatic species can trap and contain pollutants, such as sediments and fertiliser run-off.

It is a technique that can be used in domestic settings. A domestic greywater or stormwater runoff system can incorporate gardens with appropriate species and make use of grey water or rainwater to add to gardens and reduce water wastage at the same time.

Managing heat

One of the major ways green infrastructure is being used is to mitigate the urban heat island effect. City of Sydney and City of Melbourne are actively working to increase urban green space to reduce the impact of rising summer temperatures and reduce the need for energy-sucking mechanical cooling on hot days.

Landscaping experts recommend trees be positioned to deliver shade to the hottest sides of a dwelling – the southern and western sides. Deciduous species are a good choice because when they lose their leaves in winter, sunshine can warm a home. Climbing plants on trellises can also be used where conditions are not suitable for trees, for example, where space is constrained.

For apartment dwellers with southern-facing or western-facing balconies, plants such as  climbing green beans, squash or tomatoes, can be grown in modular self-wicking garden beds or in large pots and planters.

Outdoors is not the only place where green infrastructure is gaining ground. NASA research looking at the role of indoor plants to ensure air quality for space stations has been applied back on earth.

Plants absorb chemicals such as volatile organic compounds, add oxygen to the air and improve people’s mental health and wellbeing.

Find out more

There are many resources available for adding some green infrastructure to your home, workplace, neighbourhood or development. Here’s a few to get you started: